Benefits of Cool Roofs - RCI Interface Magazine
"Benefits of Cool Roofs on Commercial Buildings"
An article in RCI Interface Magazine - July 2009 - by Stanley P Graveline
Article excerpt: (emphasis added)
ENERGY AND COST IMPACTS
"Not surprisingly, the greatest impact due to change from a conventional gray roof surface to a cool roof is achieved in hot states.... However, it is clear that even the coldest states can benefit from significant reductions in cooling energy through the use of cool roofs. ...
If reflective roofs are beneficial in cooling-dominated climates, one would intuitivelyassume that such roofs would be disadvantageous in heating-dominated climates.... There should, in effect, be a 'heating energy penalty' associated with the use of cool roofs in such climates. According to the [Lawrence Berkeley National Laboratory] paper, there can be, although the magnitude is surprisingly small, even in the coldest states.... There are a number of reasons for this. Snow may cover the roof for extended periods of time. Winter days are shorter and cloudier and the sun is lower.... In other words,a horizontal surface in the northern states receives about three to five times more daily sun in the summer than in the winter.
The authors [of the Lawrence Berkeley National Laboratory paper] found that the reduction in annual cooling load exceeded the increase in annual heating load everywhere in the U.S. except the most remote areas of Alaska."
BOTTOM LINE: Cool roofs can save energy, no matter where the building is located.